Quick-freeze installation with radiant cooling



June 11, 1968 W. H. MARTIN QUICK-FREEZE INSTALLATION WITH RADIANT COOLING Filed Feb. 5, 1967 fix/A2 z;

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QUICK-FREEZE INSTALLATION WITH RADIANT COOLING Filed Feb. 3, 1967 3 SheetsSheet 2 6* Rh m A! y; f 2 W I m/ j 2 i 7 Z /.i 2 if "I w y, Z 26 if 6 //Z {I W 1/2 IN VEN TOR.

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QUICK-FREEZE INSTALLATION WITH RADIANT COOLING Filed Feb. 5, 1967 3 Sheets-Sheet 5 .2. -7- /z/ a /47E Z .z' -5- an 5/ 4 E I N VEN TOR. (7% Q I a! Z lfl BY v /0/ $57 2,

Ar-rorewevs United States Patent 3,387,464 QUICK-FREEZE INSTALLATIUN WITH RAHIANT CUULING Walter H. Martin, 2% Atwater,

San Antonio, Tex. 78213 Filed Feb. 3, 1967, Ser. No. 613,809 7 Claims. (Cl. 62--38) ABSTRACT OF THE DISCLUSURE A conveyor belt carrying the articles to be refrigerated has an upper run which is supported for travel along shallow pans of liquid refrigerant and in heat conducting contact with such liquid. The pans have laterally disposed troughs for catching overflow or leakage beneath margins of the belt. The overflow drains through outlets from the troughs leading to a pump which forces the liquid through cooling means and back through horizontal nozzles into the pans. Idler rollers are disposed in the pans for supporting the belt, and the margins of the pans are provided with leveling guide strips for the belt. Refrigcrating coils are disposed in close proximity to the upper article supporting surface of the belt for heat transfer by radiation. Adjustment means are provided for the pans, the conveyor belt, and the belt sheaves.

This invention relates to refrigeration apparatus and more particularly to apparatus for extremely quick freezing of flat articles, such as certain kinds of comestibles carried on a travelling belt which is subjected to very low temperatures as it travels through the apparatus.

The prior art is replete with examples of apparatus of this general description and various means have been employed for reducing the temperatures of the areas in proximity to both the upper and lower sides of the belt, whether by means of convection, conduction, or radiation from various sources of cold. Most frequently encountered among such means are air blasts, liquid sprays, and surface-to-surface contact by the belts with metallic cooling units.

These devices have worked with various degrees of efliciency, but the applicant has found that improved results can be attained in the quick freezing of successively transported articles by the novel means provided by the present invention.

In its preferred embodiments, the invention contemplates the provision of low temperature means closely adjacent the upper surface of the conveyor belt for drawing the heat therefrom and from the articles or products carried thereon, almost entirely by radiation, the density of construction of the low temperature means, and the close proximity of said means to the surface of the belt inhibiting convection currents to a marked degree, and of course no air blasts are employed.

The bottom surface of the conveyor belt rides in contact with pools of cooling or refrigerating liquid whereby said surface is deprived of its heat content by conduction through contact with the body of liquid.

Important novelty in the present invention also resides in the means for providing such contact while the upper run of the belt is travelling through the installation.

One or more shallow pans are provided beneath the belt, and supporting rollers are provided within the pans for the upper run of the belt, as well as horizontally directed nozzles for replenishing the supply of refrigerant liquid and imparting some slight motion thereto. Troughs are provided alongside of the pans for catching any overflow of refrigerant which may pass beneath the margins of the belt, the overflow liquidbeing caught and recirculated through a cooler and pumped back to the pans.

Adjustable leveling means are provided along the margins of the pans for properly supporting the belt and the pans themselves are adjustable for variations in height and level.

Other objects and features of novelty will be apparent from the following specification when read in connection with the accompanying drawings in which one embodiment of the invention is illustrated by way of example.

In the drawings:

FIGURE 1 is a somewhat diagrammatic view in side elevation of an installation embodying the principles of the invention;

FIGURE 2 is a fragmentary view on an enlarged scale in vertical longitudinal section through one of the pans over which the conveyor runs;

FIGURE 3 is a fragmentary top plan view of a portion of the apparatus showing one of the brine pans in top plan;

FIGURE 4 is a view in transverse vertical section through the conveyor and cooling apparatus taken on line 4-4 of FIGURE 1 through one of the pans;

FIGURE 5 is a fragmentary further enlarged view through one of the pans adjacent one of the supply nozzles;

FIGURE 6 is a greatly enlarged fragmentary sectional view through an edge of one of the pans;

FIGURE 7 is a fragmentary plan view of the conveyor drive and mounting at the left-hand end of FIGURE 1, but on an enlarged scale;

FIGURE 8 is a vertical longitudinal sectional view taken on line 8-3 of FIGURE 7; and

FIGURE 9 is a diagram of the recirculating flow of the refrigerant.

As viewed in general aspect in FIGURE 1 of the drawings, the installation is seen to comprise a basic supporting framework It), a stand or pedestal ill at one end of the device supporting a conveyor driving motor suggested at 12, and a driving sheave 13 for the conveyor belt 15.

At the opposite end of the installation is a stand designated generally by the reference character and serving to adjustably support the opposite sheave 21 for the conveyor belt 15. These belt mountings will be described in detail in connection with other figures of drawing.

The framework of the apparatus comprises also a superstructure designated generally by the reference character 25 and which includes the longitudinal laterally disposed channel beams 26 and the suspension means 27 for the upper refrigeration devices.

The supporting framework is shown in more detail in FIGURE 4 of the drawings where the channel beams 26 are shown as supported by posts 30 and the superstructure 25 is seen to include the standards 32 which serve to support the longitudinal members 33 and the cross beams 35' which constitute portions of the supporting means 27 for the upper heat exchange elements which will be described in detail presently.

Referring now more particularly to FIGURES 2, 3, 4 and 5, the lower refrigerating means for cooling the underside of the upper run of the belt 15 will be described. Extending longitudinally of the installation are a series of shallow trays having end walls 41 interlocked as indicated at 42 in FIGURE 2, and side walls 43 having inwardly directed flanges 44 at the upper edges thereof.

These pan or tray sections 40 are supported at intervals along the apparatus by the cross frames 45 which are in turn supported for vertical adjustment from the channel beams 26 by means of the threaded bolt and nut devices 46, shown best in FIGURE 4 of the drawings.

Within the tray sections 4% are nested the inner pans 543 which comprise means for containing relatively shallow pools of refrigerating liquid. The pans have side e2 walls 51 and end walls 52, the side walls terminating at their upward edges in outwardly directed flanges 5d preferably at the same level as the flanges 44- f the larger tray 40. The inward pans 59 may be secured centrally of the outer trays it? by any suitable means.

As best shown in FIGURES and 6 of the drawings, guiding and leveling supports for the belt are carried by the side walls 51 of the pans 5-3. This guiding means is comprised by the elongated strips or plates 6%, conveniently made of wood or some other material softer or less abrasive than metal, and these strips are bolted to the walls 51 as clearly shown at 61 in FIGURE 6. The upper edges of the strips 60 project upwardly beyond the flange 54 of the pan and disposed in parallel relation with the strip or plate 6 is the additional outer strip 62 which rests upon the flange 54 of the wall 51 of the pan and is secured to and spaced from the plate or strip by means of the bolt and nut connection 64 and the spacer element 65.

Means are also provided for supporting the belt 15 in its travel along the pans and these include the sets of idler wheels or rollers 71, the wheels being carried upon the transverse axle 72 which is supported by the brackets 74 which extend upwardly from the transverse bar 75 which may be of any angle section or of any suit able configuration. The respective ends of the bar '75 are secured as by means of the angle brackets 76 to the side guide structure 60, 62 or directly to the side wall 51 of the inner pan 50.

For further leveling support of the belt, transverse strips 78 are secured across the ends of the pans 50 just inside of the end walls 52 and may be attached by bolts similar to those indicated at 64 which support the lat eral guide strips 60.

It will thus be seen that the belt 15 is supported in level position throughout the length of the apparatus by the lateral guides 65), 62, the end guide strip '78, and the idler wheel installations 70. Height adjustment and angular adjustment of the belt may be effected by suitable adjustment of the nut and bolt supporting means 46 associated with the channels 26 of the side frame structure.

Liquid refrigerant is supplied to the inner pans 5G by means of the nozzle structures designated generally by the reference numeral 30 and best seen in FIGURES 2, 3 and 5. Any suitable number of these installations may be disposed within the pans, but five are indicated in FIGURE 3. Cross conduits 81 are supported by means of the T 82 carried by the depending nipple 83 which extends through the bottom walls of the pans 40 and 59 as clearly shown in FIGURE 5 and to which a recirculating conduit may be applied as suggested at 84. The pipes 30 are capped at each end as at 86 and nozzles 37 are disposed at spaced intervals along the pipes. The nozzles 87 are disposed horizontally and serve to give a certain amount of flow to the refrigerant liquid and to keep the pans full to overflowing so that conductive contact is always maintained with the conveyor belt 15 as it passes over the trays.

Due to the continual replenishing of the liquid in the trays there is overflow over the lateral structure of the pans 50 and beneath the belt and the liquid. Thus overflowing is caught within the troughs 9% provided between the side walls 43 and 51 of the respective pans. A nipple 91 is indicated in FIGURE 5 and suitable connections are provided for carrying the overflow liquid to a pump P from which it may be pumped through refrigerating means 150 and back to the pans through the intake nipples 83. (See FIGURE 10.)

Of course, means must be provided for draining the pans 50 on occasion and this may be very readily effected through the nipple 95 shown centrally of FIG- URE 4.

Means for applying refrigeration to the articles carried upon the top surface of the belt 15 will now be described.

Supported by means of the adjustable hook elements 19:0 from the lower flange of the cross beam 35 are the pipes 191 each provided with a multiplicity of closely spaced radiating fins 162. These finned pipe units are spaced rather closely together, only a narrow interval 103 remaining in between. Also, and this is a rather important feature of the installation, the upper refrigerating system 1614M is disposed quite closely to the upper surface of the belt 15, the interval indicated at a in FIG- URE 4, being preferably within the range of say two or three inches up to possibly five or six inches, an optimum distance for most flat articles such as certain flat comestibles, being about three and one-half inches. Of course, suitable intake and outlet nipples are provided such as suggested at 105 and return-bends such as indicated at 106 at the respective opposite ends of the installation as shown in FIGURE 1 of the drawings.

It will thus be seen that there is provided by means of the present invention a highly efficient quick cooling installation whereby the bottom surface of the conveyor belt is maintained in direct conductive contact with a body of liquid refrigerant, and the upper surface maintained in very close radiant heat exchange juxtaposition with the upper cooling means.

While the close positioning of the various parts of the upper cooling system 101 would to a very great degree eliminate convection currents and supply the cooling effect practically entirely by radiation, any sort of enveloping closure such as the hood 160 may be provided embracing the upper portion of the belt and the upper cooling installation, to prevent uneven convection currents in the adjacent atmosphere.

Some convenient supporting and driving means for the conveyor belt will now be described. The return run of the belt 15 may be supported by the rollers 110 carried upon the shaft or axle 111 which in turn is supported by the brackets or pedestals 112, the whole installation being seated upon the cross member 114, suitably anchored to the basic frame structure 10 all as shown in FIGURE 4 of the drawings.

As shown in FIGURE 1 of the drawings the belt at the right-hand end of the installation passes around the sheave 13 and at the opposite end around the sheave 21 which may be adjusted to determine the proper tension in the belt during operation. This may be effected by the means best illustrated in FIGURES 7 and 8 of the draw ings. The sheave assembly 21 (which in this instance may comprise four individual sheave elements 121 having appropriate tires 122 and mounted upon the shaft or axle 125) is carried by the slidable bearing block structure 127 which is in turn supported upon the stand or base 20. Extending from one side of each of the bearing block assemblies 127 are the rods 130 which are threaded through the blocks 131 secured between the parallel plates 132, which plates are pivoted as at 133 to an upstanding flange 134 carried by the squared cross shaft 135. Depending upon the cross shaft 135 are the brackets 136 through which extend the rods 137. The rods 137 are received for sliding movement within the sleeves 138 which may be secured as by welding to the upper side of the channel cross piece 139 extending across the frame 20. The righthand ends of the shafts 137 pass through the spaced discs 140 and 141 and nuts 142 are threaded upon the extreme outer end of the shafts.

Between the abutment discs 140 and 141 there is disposed the coil spring 145 which urges these abutments apart and in this way urges the shaft 137 toward the right and thrusts the rod 130 toward the left, thus urging the bearing blocks 127 and the sheave installation 21 in a direction to yieldably tauten the belt 15.

It is understood that various changes and modifications may be made in the embodiment illustrated and described herein without departing from the scope of the invention as defined by the following claims.

Having thus described the invention, what is claimed 1. A quick-freeze installation comprising, in combination, a supporting framework, a substantially horizontally disposed endless belt conveyor, means for driving said conveyor to carry articles to be cooled through said installation; refrigerating means disposed beneath the upper run of said conveyor and in conduction heat exchange contact with the bottom surface of said belt conveyor, said refrigerating means comprising a pool of liquid refrigerant; radiant refrigerating means disposed above the upper run of said conveyor and in close juxtaposition with the top surface thereof and with the articles carried thereon, said last named refrigerating means so constructed and positioned as to obstruct any significant flow of air adjacent said conveyor whereby the top cooling is substantially all by radiation, said upper radiant refrigerating means comprising finned tubes, including vertically disposed relatively parallel fins.

2. The installation as set forth in claim 1 wherein said liquid refrigerant is contained in a shallow pan supported beneath said upper run of the conveyor, and the side wall structure of said pan is disposed to be in supporting contact with the bottom surface of said belt conveyor, and there are provided means for continually supplying said pan with liquid refrigerant so that a certain amount of overflow occurs over the wall structures of said pan and beneath the superposed marginal portions of the belt conveyor, and means for receiving such overflow laterally outwardly of the pan.

3. The installation as set forth in claim 2 in which said side Wall structure includes non-rnetallic guiding and leveiing strips secured along the upper edges of the walls of said pan for sliding contact with the underside of said belt conveyor, and means are provided for adjusting the height of each side of said pan upon said framework.

4. The installation as set forth in claim 2 in which sets of idler rollers are mounted in said pan for the anti-friction support of the intermediate portions of the upper run of said belt conveyor.

5. The installation as set forth in claim 2 in which the liquid supplying means comprises a recirculating system including a pump, a source of refrigeration, and horizontally discharging nozzles within said pan.

6. The installation as set forth in claim 1 in which the upper radiant refrigerating means comprises finned tubes disposed at an approximate distance of about three and one-half inches above the top surface of the belt conveyor.

7. The installation as set forth in claim 1 in which said endless belt conveyor is trained about large sheaves at each end of the installation, and spring; means is provided for yieldingly urging one of said sheaves toward belt tautening position.

References Cited UNITED STATES PATENTS 1,753,828 4/1930 Greer et al 62-380 X 1,738,706 12/1929 Hoifmann 62-380 X 1,940,164 12/1933 Comer 62-380 2,783,618 3/1957 Mills 62-380 2,844,359 7/ 1958 Annerhed 62-380 X 2,974,497 3/1961 Carpenter et a] 62-63 3,280,590 10/1966 Larsson cccccccccccc 62-380 ROBERT A. OLEARY, Primary Examiner.

W. E. WAYNER, Assistant Examiner. 

